U.S. patent number 5,793,608 [Application Number 08/661,817] was granted by the patent office on 1998-08-11 for cooling system for enclosed electronic components.
This patent grant is currently assigned to Sun Microsystems, Inc.. Invention is credited to Gary A. Harpell, Nagaraj Mitty, Alan Lee Winick.
United States Patent |
5,793,608 |
Winick , et al. |
August 11, 1998 |
Cooling system for enclosed electronic components
Abstract
An enclosure contains, among other components, hard drive
cartridges, graphics or other option cards, power supply and a CPU
and its support chips. The total power in the whole enclosure is
about 325W and the CPU consumes about 30W of this total. For design
purposes the components are closely positioned and hence heat
dissipation is an important problem. Plural fans, as hereinafter
disclosed, are used to circulate air. For the hard drive cartridges
a fan snapped into a sidewall of the enclosure draws air from
apertures in the bottom through the cartridge and into a plenum.
For the CPU, an impingement fan discharges air directly downward on
a heat sink positioned over the chip and into the plenum. Bulk flow
fans discharge air from air intake vents in side walls of the
enclosure as well as air discharged from the hard drive and CPU
through an internal wall into a separate sub-enclosure for the
power supply and thence to the exterior. Conventional fans are used
but are positioned and inter-related so that the noise level is
tolerable.
Inventors: |
Winick; Alan Lee (San Jose,
CA), Mitty; Nagaraj (San Jose, CA), Harpell; Gary A.
(San Carlos, CA) |
Assignee: |
Sun Microsystems, Inc.
(Mountain View, CA)
|
Family
ID: |
24655234 |
Appl.
No.: |
08/661,817 |
Filed: |
June 11, 1996 |
Current U.S.
Class: |
361/695;
257/E23.099; 361/679.33; 361/679.4; 361/679.49; 361/679.51;
361/679.54 |
Current CPC
Class: |
G06F
1/20 (20130101); H01L 23/467 (20130101); H01L
2924/0002 (20130101); H01L 2924/0002 (20130101); H01L
2924/00 (20130101) |
Current International
Class: |
G06F
1/20 (20060101); H01L 23/467 (20060101); H01L
23/34 (20060101); H05K 007/20 () |
Field of
Search: |
;361/687-688,690,694-697 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
3306696 |
|
Dec 1988 |
|
JP |
|
5206668 |
|
Aug 1993 |
|
JP |
|
Primary Examiner: Thompson; Gregory D.
Attorney, Agent or Firm: Flehr Hohbach Test Albritton &
Herbert LLP Caplan; Julian
Claims
What is claimed is:
1. In combination, an enclosure comprising a bottom and four
peripheral sides extending substantially vertically upward from
said bottom, a first said side being formed with air inlet first
apertures, a motherboard on said bottom, a heat emitting chip
positioned on said motherboard, a heat sink above said chip, said
heat sink comprising a base resting on said chip and a plurality of
vertical fins extending upward from said base, a power supply area
adjacent a second said side, a partition parallel to said second
side and spaced inwardly of said power supply area, and said
partition being in close proximity to said chip, said partition and
said first, third and fourth sides defining a plenum, said second
side being formed with air discharge second apertures, a top formed
with a fan aperture above said heat sink, an impingement first fan
located in said fan aperture discharging air from said plenum
downward to cool said heat sink and said chip, said top engaging
said partition,
a second fan in said partition discharging air from said plenum and
air emitted from said heat sink and said chip through said power
supply area and out through said second apertures.
2. The combination of claim 1 which further comprises a plurality
of second chips on said motherboard, said impingement fan
discharging air on said second chips.
3. The combination of claim 2 which further comprises tower disk
heat sinks on said second chips, air discharged by said impingement
fan cooling said tower disk heat sinks.
4. The combination of claim 1 which further comprises a plurality
of heat emitting electronic components in said plenum, said
electronic components comprising at least one disk drive adjacent
said third side, a hard drive fan adjacent but spaced inward of
said third side directing air toward said at least one disk drive,
a plurality of vents formed in said bottom adjacent said third
side, said hard drive fan drawing air upward through said vents and
then inwardly of said enclosure toward said disk drive and a
cartridge fitting into said third side, said hard drive fan being
detachably mounted in said cartridge.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a new and improved cooling system for
enclosed electronic components, such as the important components of
a computer.
2. Related Art
Computer housings typically contain a chassis which supports an
outer cover or shell. Within the chassis are various electronic
components which generate heat during operation. Such components
include electronic cards which are plugged into a motherboard, a
power supply and storage devices such as hard disk drives and
floppy disk drives, among others. Prior art computers typically
contained one or more fans which created a flow of air to remove
the heat generated by the components.
The size of a fan used in such a housing is limited by the height
of the chassis. An electrical system which generates more heat than
an existing design must be accompanied by more fans or fans which
create a higher flow rate. The flow rate is typically increased by
raising the voltage level provided to the fan motors, but this
undesirably increases the noise emitted by the fan.
The advantage of the present invention over prior systems is more
efficient cooling without emitting an undesirable level of
noise.
SUMMARY OF THE INVENTION
The present invention cools many heat-emitting electronic
components within an enclosed area. For example, a
motherboard-based CPU cluster used with the present invention
dissipates heat from approximately 45 watts located in a 10 square
inch area of the board and included therein is a CPU chip occupying
about 2 square inches which dissipates heat from 30 to 35 watts of
power. Other chips clustered around the CPU consume in total around
45 watts. Industry standards require that the acoustic level be
less than 5 Bels for the use of the device as desktop office
equipment. The system further must be used where ambient
temperatures are in the range of -20.degree. C. to 40.degree. C.
and at an altitude from sea level to 10,000 feet. At the same time,
venting restrictions in the front face of the enclosure are imposed
by reason of industrial design requirements.
In addition to the motherboard heat emitting area, within the
enclosure are hard drive devices as well as graphic boards and
other circuit boards so that the total power delivery may be within
the range of 180 watts to 230 watts.
One feature of the invention is the use of an impingement fan which
spot cools the CPU chip by blowing directly on it. This air is
simultaneously removed from the enclosure by a power supply fan
adjacent the impingement fan. Extraordinary, unique thermal density
dissipation is obtained.
The support chips for the CPU, including SRAMS and data buffer
chips, are located adjacent the CPU chip as needed for electrical
performance of the device. The proximity of hot chips poses
additional thermal problems. The ancillary chips are cooled by
tower disk heat sinks and are cooled by the fan system herein
described.
Disk drives are located adjacent the front of the enclosure. An
optional snap-in front fan cools the disk drives by blowing air
directly over the disk drives. The front fan draws air from vents
which are located at the intersection of the bottom of the
enclosure and the front so that the air is drawn up from the vents
into the fan and thence against the disk drives. Hence, no grills
are visible from the front of the enclosure.
The fan which cools the disk drives, when used, is mounted in a
cartridge which is snapped into a cavity behind the front wall and
the fan is set back from the front wall a sufficient distance so
that the air can circulate up from the bottom vents through the fan
and thence into the disk drives. A thermistor on the fan senses
ambient air temperature, thereby increasing the speed of the fan by
regulating the voltage of its motor.
Power supply fans are controlled by another thermistor on the
motherboard at the inlet side so that internal configuration does
not impact the fan speed. This provides quiet room temperature
performance while cooling adequately even at high altitudes and
high temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS:
The accompanying drawings, which are incorporated in and form a
part of this specification, illustrate embodiments of the invention
and, together with the description, serve to explain the principles
of the invention:
FIG. 1 is a perspective view of the enclosure in which the present
invention is installed, the cover being removed for clarity of
illustration.
FIG. 2 is a top plan view of the structure of FIG. 1.
FIG. 3 is an exploded perspective view of a portion of the
motherboard and CPU, its heat sink and its impingement fan.
FIG. 4 is a perspective view of a portion of the device showing the
hard drive installed in the front wall.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments
of the invention, examples of which are illustrated in the
accompanying drawings. While the invention will be described in
conjunction with the preferred embodiments, it will be understood
that they are not intended to limit the invention to those
embodiments. On the contrary, the invention is intended to cover
alternatives, modifications and equivalents, which may be included
within the spirit and scope of the invention as defined by the
appended claims.
Enclosure 11 is formed with a substantially rectangular bottom 12
of a size to accommodate the various electrical components required
in close proximity to each other, and it is the proximity of these
components which raises the ventilating problems which the present
invention solves. Extending upward from the four edges of bottom 12
are vertical sides. A cover 15 closes off the top of the enclosure,
but for purpose of illustration this cover is removed so that the
components within the enclosure are more readily apparent.
The first side or front 13 of enclosure 11 is intended to be
ornamental. To preserve the ornamental appearance, ventilating
vents 14 are formed in bottom 12 near the intersection of lower
edge of front 13 so that air is drawn in through the vents without
destroying the aesthetic appeal of the front 13.
The second side 17 is formed with a plurality of air inlet
apertures 18, it being understood that most of the cooling air for
the enclosure is drawn therethrough. Third side 19 is at the back.
Since the back is frequently placed against a wall, ventilation
apertures are not formed therein. The fourth side 21 is formed with
plural discharge vents 22. An internal partition 23, generally
parallel to the side 21, closes off an area in which power supply
28 (not shown) is located. An enlarged plenum 24 or input-output
section is created within the enclosure 11.
Located in proximity to front 13 are hard drive units 26. Graphic
cards 27 may be installed inwardly of the hard drive units 26 and
other circuit boards (not shown) may be located within plenum
24.
Hard drive fan 31 is optional. When used, it is mounted in a
cartridge 32 which snaps into an enclosure 33 behind front 13 so
that the fan is spaced inwardly of front 13 about 1/4 inch. A
thermistor (not shown) in proximity to fan 31 controls the voltage
and, accordingly, the rpm of fan 31. Hence, air is drawn up through
vents 14 through the fan 31 and against the hard drive units 26 to
cool the same. The air then travels into the plenum 24.
Within plenum 24 is the greatest heat emitting area located on a
motherboard 26 which rests on bottom 12. The hottest element on
motherboard 36 is a CPU chip 37 (see FIG. 3) using 35 watts of
power. Positioned above the chip 37 is the base 38 of a heat sink.
Fins 39 extend upward from base 38. Located above the upper ends of
the fins 39 is a top 41 in which is mounted an impingement fan 42
which constitutes a thermal cooling module which blows air directly
on the fins 39, base 38 and chip 37. The chip 37 is located in
proximity to other support chips such as data buffers and SRAMS
which bring the total power requirement of motherboard 36 to about
45 watts. These elements have heat sinks 43 such as tower disk heat
sinks located around the heat sink base 38 and are likewise cooled
by the fan 42.
An important feature of the invention is the fact that the fan 42
is located in proximity to the bulk flow system fans 46 which are
mounted in interior partition 23. It is a feature of the invention
that the air discharged by the fans 42 is drawn out of plenum 24 by
the fans 46 in close proximity thereto. Fans 46 drive the
discharged air against the power supply and out through vents
22.
The fans collectively hold the acoustic level below 5 Bel range.
This is acceptable for desk top equipment.
The foregoing descriptions of specific embodiments of the present
invention have been presented for purposes of illustration and
description. They are not intended to be exhaustive or to limit the
invention to the precise forms disclosed, and obviously many
modifications and variations are possible in light of the above
teaching. The embodiments were chosen and described in order to
best explain the principles of the invention and its practical
application, to thereby enable others skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated. It
is intended that the scope of the invention be defined by the
claims appended hereto and their equivalents.
* * * * *